ABLATION PROCESSING METHOD, ABLATION PROCESSING DEVICE, SUBSTRATE AND METHOD FOR PRODUCING A SUBSTRATE

Abstract

The present invention provides an ablation machining method for forming a recess in a surface of a substrate by ablation machining with irradiation energy of a laser beam, wherein an irradiation area in one shot of the laser beam onto the substrate is set to be smaller than a region of the substrate to be machined, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be machined, and wherein in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved with respect to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction,A portion of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first and second directions, thereby forming the recess with a depth within a defined range in the area of ​​the substrate to be processed. In this way, a recess with the desired depth can be obtained with a simple process, while preventing penetration of the layer due to excessive processing.

Description

TECHNICAL FIELD

[0001] The present invention relates to a method for ablation processing, an apparatus for ablation processing, a substrate and a method for producing a substrate. STATE OF THE ART

[0002] Semiconductor packaging substrates are trending away from “More Than Moore” towards “System-on-Chip” (SoC), where a system is integrated into a chip, and in line with this trend, the latter are being actively developed.

[0003] Furthermore, semiconductor package substrates have increasingly more complex and dense configurations, and facilities using an excimer laser have been used to manufacture the base substrates.

[0004] For example, Patent Document 1 describes a laser machining method for forming a workpiece to a predetermined depth position with a laser beam, which is characterized in that the laser power of the laser beam and a relative moving speed between the workpiece and the laser beam are increased such that the energy per unit length of the laser beam, which is optimally adjusted depending on the workpiece, falls within an energy range that does not penetrate the workpiece even if the laser power is increased due to power fluctuations in a laser beam oscillator, and thus the number of irradiations required for laser machining is reduced.

[0005] Patent Document 2 describes a laser machining method for sequentially irradiating a portion to be drilled of a workpiece with a laser beam having a smaller beam cross section than the portion to be drilled to machine the portion to be drilled, characterized in that the method includes: a first machining step of sequentially irradiating the entire portion to be drilled with a laser beam having a beam cross section of a first shape and forming a first irradiation region corresponding to the beam cross section of the first shape on the workpiece;and a second processing step of sequentially irradiating the area to be drilled with a laser beam having a beam cross-section of a second shape smaller than the first shape, and forming a second irradiation area corresponding to the beam cross-section of the second shape on the workpiece, wherein the laser beam forming the first irradiation area is sequentially emitted in the first processing step to form an overlapping area in which parts of the first irradiation area overlap with each other, and the laser beam forming the second irradiation area is sequentially emitted in the second processing step so that the second irradiation area is enclosed in a different area than the overlapping area of ​​the area to be drilled. LIST OF CITATIONSPATENT LITERATURE Patent Document 1: JP 2009-22978 A Patent document 2: WO 2013 / 094025 A1 SUMMARY OF THE INVENTION TECHNICAL PROBLEM

[0006] For example, Patent Documents 1 and 2 described above propose laser processing methods that involve overlapping laser beam irradiation areas. These methods require precise alignment of the ends of the laser beam irradiation areas. Without micrometer-level alignment, as in, for example, Fig. 17, excessive machining may possibly be performed so that a portion 88 is formed with a very large machining depth, which may penetrate a substrate 80, or conversely, a hole may be formed in the substrate 80, as in Fig. 18, a section 89 may only be partially formed. As a result, conventional methods have problems such as the risk of layer penetration and a partial failure to obtain a desired pattern.

[0007] There is also a need for a substrate from which high reliability can be expected.

[0008] The present invention has been made to solve the above-mentioned problems and has as its object to provide an ablation processing method with which a recess having a desired depth can be obtained with a simple operation, an ablation processing apparatus with which a recess having a desired depth can be obtained with a simple operation while reducing the risk of penetration of the layer, a substrate from which high reliability can be expected, and a manufacturing method that can manufacture a substrate from which high reliability can be expected. SOLUTION TO THE TASK

[0009] In order to achieve the above objects, the present invention provides an ablation processing method for forming a recess in a surface of a substrate by ablation processing with irradiation energy of a laser beam, wherein an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, and in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved with respect to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the recess having a depth within a defined range in the area of ​​the substrate to be processed.

[0010] According to the ablation processing method of the present invention, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction so as to form the recess having a depth within a defined range in the region of the substrate to be processed, and thus a recess having a desired depth can be obtained with a simple operation while preventing penetration of the layer caused by excessive processing.

[0011] With the large number of radiation shots a light source that generates the laser beam by oscillation and a mask that encloses an effective area with a pattern corresponding to the recess to be formed can be used, an irradiated mask area, which is part of the effective area of ​​the mask, can be irradiated with the laser beam of the light source, an irradiated substrate area, which is at least a part of the area of ​​the substrate to be processed, can be irradiated with the laser beam passed through the mask to project a pattern onto the irradiated substrate area to thereby perform the ablation processing, and the mask and the substrate can be moved synchronously when the irradiation area of ​​the laser beam is moved relative to the substrate in a planar direction substantially perpendicular to an irradiation direction of the laser beam.

[0012] In the present invention, for example, ablation processing can be performed in this way using the mask. Furthermore, in this aspect, the area to be processed is not limited to a lens area, and thus an area (viewing angle) larger than the lens area can be processed.

[0013] Furthermore, according to this aspect, a projection optical system required for irradiation can be downsized with downsizing, and the positional accuracy of laser irradiation and temperature control can be improved. Furthermore, the size of the projection optical system can be reduced with downsizing, thereby reducing image distortion caused by irradiation.

[0014] In this case, the irradiated mask area of ​​the mask is preferably irradiated with a laser beam having a rectangular irradiation shape.

[0015] Irradiation with a laser beam having a rectangular irradiation shape can more reliably prevent penetration of the layer caused by excessive processing.

[0016] In particular, rectangular irradiation allows more efficient and precise control of the position and number of irradiations with microscopic overlap than, for example, irradiation with circular overlap.

[0017] The irradiation with laser beams is preferably carried out without stopping the mask and the substrate during the plurality of irradiation shots in the first direction and / or the second direction.

[0018] This enables more efficient ablation processing.

[0019] If a first mask and a second mask are used as a mask, the plurality of irradiation shots can be performed using the first mask, the first mask can then be replaced by the second mask, and the plurality of irradiation shots using the second mask may be performed such that a part of the irradiated substrate area of ​​the substrate in the first direction overlaps with a part of the irradiated substrate area in the plurality of irradiation shots using the first mask.

[0020] In the present invention, not just one mask, but two or more masks can be used. The use of two or more masks enables efficient processing of a larger area of ​​the substrate to be processed.

[0021] An excimer laser, for example, can be used as a laser beam.

[0022] For example, an excimer laser can be used in the ablation processing method of the present invention. The use of an excimer laser enables efficient ablation of a surface to be processed on an organic material substrate, such as an ABF substrate, and enables high-productivity processing. Furthermore, the excimer laser has low coherence, thus enabling more precise control of the position and number of microscopically overlapping irradiations.

[0023] For example, a semiconductor package substrate can be subjected to ablation processing.

[0024] The substrate to be processed is not particularly limited, but a semiconductor package substrate, for example, can be the substrate to be processed.

[0025] In particular, the processing of the semiconductor package substrate may include a processing pattern combining VIA processing and groove processing, or the like. In this case, the method of the present invention allows the VIA processing and groove processing to be performed in the same step without separating them from each other.

[0026] Furthermore, semiconductor package substrates are increasingly exhibiting denser configurations. A conventional laser drilling method for VIA processing increases processing time due to the increased number of holes to be drilled, which is associated with higher density. In comparison, the method of the present invention does not result in an increase in processing time due to a larger number of holes to be drilled or a finer pattern.

[0027] The present invention also provides an ablation processing apparatus for forming a recess in a surface of a substrate by ablation processing with irradiation energy of a laser beam, including: a light source that generates the laser beam by oscillation; a substrate positioning table supporting the substrate; and a control unit configured to perform a control such that an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, and in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved with respect to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the recess having a depth within a defined range in the area of ​​the substrate to be processed.

[0028] With the ablation processing apparatus of the present invention, a portion of the irradiation area in each shot can overlap with the irradiation area in another shot in each of the first and second directions, thereby forming the recess with a depth within a defined range in the region of the substrate to be processed. In this way, a recess with the desired depth can be obtained with a simple process while preventing penetration of the layer due to excessive processing.

[0029] Preferably, the ablation processing device further includes: a mask enclosing an effective area with a pattern corresponding to the area of ​​the substrate to be processed; and a mask positioning table which supports the mask, whereby the control unit is further configured to synchronously move the mask positioning table and the substrate positioning table in a planar direction substantially orthogonal to an irradiation direction of the laser beam.

[0030] In the ablation processing device of the present invention, for example, the mask can be used in this way. Furthermore, in this aspect, the processing area is not limited to a lens area, and thus an area (view angle) larger than the lens area can be processed.

[0031] Furthermore, according to this aspect, a projection optical system required for irradiation can be downsized with downsizing, and the positional accuracy of laser irradiation and temperature control can be improved. Furthermore, the size of the projection optical system can be reduced with downsizing, thereby reducing image distortion caused by irradiation.

[0032] In this case, the ablation processing device further includes an optical shaping system between the light source and the mask, which shapes an irradiation shape of the laser beam into a rectangular irradiation shape.

[0033] The ablation processing device according to the preferred aspect enables irradiation with the laser beam having a rectangular irradiation shape. Thus, the penetration of the layer caused by excessive processing can be more reliably prevented.

[0034] In particular, rectangular irradiation allows more efficient and precise control of the position and number of irradiations with microscopic overlap than, for example, irradiation with circular overlap.

[0035] The light source can be an excimer laser light source.

[0036] The light source can be, for example, but is not limited to, an excimer laser. The use of an excimer laser enables efficient ablation of the surface of the organic material substrate to be processed, such as an ABF substrate, and enables high-productivity processing. Furthermore, the excimer laser has low coherence, thus enabling more precise control of the position and number of microscopically overlapping irradiations.

[0037] The present invention also provides a substrate having a groove in a surface of the substrate, wherein a bottom of the groove has a plurality of recesses which are periodically arranged in the longitudinal direction of the groove.

[0038] In such a substrate, the plurality of recesses periodically arranged in the longitudinal direction of the groove can provide an anchoring effect for fixing a layer or the like formed on the substrate, thereby achieving high reliability. In such a substrate, an embedded conductive layer is less likely to peel off, which may occur during a coating step or CMP performed after the ablation processing step in the present invention, and a high-quality final product having high resistance to stress caused by thermal cycling or the like can be provided after completion of the processing.

[0039] The substrate may, for example, be a semiconductor package substrate.

[0040] This type of substrate is not particularly limited, but can be, for example, a semiconductor package substrate.

[0041] In particular, the processing of the semiconductor package substrate may include a processing pattern combining VIA processing and groove processing, or the like. In this case, the method of the present invention allows the VIA processing and groove processing to be performed in the same step without separating them from each other.

[0042] Furthermore, semiconductor package substrates are increasingly exhibiting denser configurations. A conventional laser drilling method for VIA processing increases processing time due to the increased number of holes to be drilled, which is associated with higher density. In comparison, the method of the present invention does not result in an increase in processing time due to a larger number of holes to be drilled or a finer pattern.

[0043] The present invention also provides a method for manufacturing a substrate having a groove in a surface of the substrate by ablation processing with irradiation energy of a laser beam, wherein an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, and in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved relative to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the groove with a depth within a defined range in the area of ​​the substrate to be processed, the plurality of irradiation shots are carried out such that irradiation areas with different numbers of overlaps are provided in each of the first direction and the second direction, and thereby producing the substrate in which a bottom of the groove has a plurality of recesses periodically arranged in the longitudinal direction of the groove.

[0044] With the method for manufacturing a substrate of the present invention, the substrate in which a bottom of the groove has a plurality of recesses periodically arranged in the longitudinal direction of the groove can be manufactured. In such a substrate, the plurality of recesses periodically arranged in the longitudinal direction of the groove can provide an anchoring effect for fixing a layer or the like formed on the substrate, thereby achieving high reliability.

[0045] According to such a manufacturing method, an embedded conductive layer is less likely to peel off, which may occur during a coating step or CMP performed according to the manufacturing method of the present invention, and a high-quality final product having high resistance to stresses caused by thermal cycling or the like can be provided after completion of processing. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0046] As described above, according to the ablation processing method of the present invention, a recess having the desired depth can be obtained with a simple operation while preventing penetration of the layer caused by excessive processing.

[0047] Furthermore, according to the ablation processing apparatus of the present invention, a recess having a desired depth can be obtained with a simple operation while preventing penetration of the layer caused by excessive processing.

[0048] Furthermore, it can be assumed that a substrate of the present invention provides a package substrate with the desired reliability.

[0049] Furthermore, according to the method for manufacturing a substrate of the present invention, a substrate expected to have high reliability can be manufactured. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic diagram of an example of an ablation processing apparatus of the present invention; Fig. 2 is a schematic diagram showing an example of a region of irradiation with a laser beam in one shot in the ablation processing method of the present invention; Fig. 3 is a schematic diagram of an example of overlapping irradiation in the ablation processing method of the present invention; Fig. 4 is a schematic diagram of an example of overlapping irradiation in the ablation processing method of the present invention; Fig. 5 is a schematic diagram of an example of overlapping irradiation in the ablation processing method of the present invention; Fig. Figure 6 is a schematic plan view of a part of the substrate after the overlapping irradiation of Fig. 5; Fig. 7 is a schematic diagram showing an example of overlapping irradiation in the ablation processing method of the present invention; Fig. 8 is a schematic diagram showing an example of overlapping irradiation in the ablation processing method of the present invention; Fig. 9 is a flowchart of an example of a method for ablation processing of the present invention; Fig. 10 is a schematic diagram of an example of ablation processing in the example of Fig. 9; Fig. 11 is a schematic diagram showing an example of overlapping irradiation for forming a recess in a bottom of a groove; Fig. 12 is a schematic diagram showing an example of overlapping irradiation in which the formation of a depression in a bottom of a groove is suppressed; Fig. 13 is a schematic diagram of another example of overlapping irradiation in which the formation of a depression in a bottom of a groove is suppressed; Fig. 14 is a schematic diagram showing an example of ideal irradiation for preventing the formation of a depression in the bottom of the groove; Fig. 15 is a schematic diagram of overlapping irradiation in a reference example; Fig. 16 is a schematic diagram showing an example of overlapping irradiation for suppressing the formation of the recess in the bottom of the groove; Fig. 17 is a schematic diagram of an example of conventional ablation processing; and Fig. 18 is a schematic diagram of an example of conventional ablation processing. DESCRIPTION OF THE EMBODIMENT

[0050] As described above, it is desired to develop an ablation processing method that can obtain a recess having a desired depth with a simple operation while reducing the risk of penetration of the layer, an ablation processing apparatus that can obtain a recess having a desired depth with a simple operation while reducing the risk of penetration of the layer, a substrate from which high reliability can be expected, and a manufacturing method that can manufacture a substrate from which high reliability can be expected.

[0051] The inventors of the present invention have carefully studied the above-described objects and found that by overlapping a part of an irradiation area in each shot with an irradiation area in another shot in each of the first direction and the second direction so as to form the recess having a depth within a defined range in the region to be processed of a substrate, a recess having a desired depth can be obtained with a simple operation while preventing penetration of the layer caused by excessive processing, thereby completing the present invention.

[0052] The inventors of the present invention have also found that a substrate in which a plurality of recesses are periodically arranged in a longitudinal direction of a groove can provide an anchoring effect for fixing a layer or the like formed on the plurality of recesses, and high reliability of a semiconductor package substrate can be expected, thereby completing the present invention.

[0053] That is, the present invention is an ablation processing method for forming a recess in a surface of a substrate by ablation processing with irradiation energy of a laser beam, wherein an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, and in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved with respect to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the recess having a depth within a defined range in the area of ​​the substrate to be processed.

[0054] The present invention is also an ablation processing apparatus for forming a recess in a surface of a substrate by ablation processing with irradiation energy of a laser beam, which includes: a light source that generates the laser beam by oscillation; a substrate positioning table supporting the substrate; and a control unit configured to perform a control such that an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, and in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved with respect to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the recess having a depth within a defined range in the area of ​​the substrate to be processed.

[0055] The present invention also relates to a substrate having a groove in a surface of the substrate, wherein a bottom of the groove has a plurality of recesses which are periodically arranged in the longitudinal direction of the groove.

[0056] The present invention also relates to a method for producing a substrate having a groove in a surface of the substrate by ablation processing with irradiation energy of a laser beam, wherein an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, and in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved relative to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the groove with a depth within a defined range in the area of ​​the substrate to be processed, the plurality of irradiation shots are carried out such that irradiation areas with different numbers of overlaps are provided in each of the first direction and the second direction, and thereby producing the substrate in which a bottom of the groove has a plurality of recesses periodically arranged in the longitudinal direction of the groove.

[0057] The present invention is described in detail below, but is not limited thereto. [Ablation processing facility]

[0058] Fig. 1 is a schematic representation of an example of an ablation processing device of the present invention. In the ablation processing device 100 of Fig. 1 is an ablation processing device for forming a recess in a surface of a substrate 80 by ablation processing with irradiation energy of a laser beam 4. It should be noted that the ablation processing device 100 of Fig. 1 is an example of an ablation processing device of the present invention, but the ablation processing device is not limited to the device of Fig. 1 is limited.

[0059] The facility for ablation processing 100 of Fig. 1 includes a light source 11 that generates the laser beam by oscillation, a substrate positioning table 40 that supports the substrate 80, and a control unit 90.

[0060] More specifically, the ablation processing device 100 in the example of Fig. 1 a first optical functional part 10 and a second optical functional part 20.

[0061] The light source 11 that generates the laser beam by oscillation is a light source (laser oscillator) 11 that applies (emits) a pulsed laser beam 1 and is enclosed in the first optical functional part 10. For example, an excimer laser can be used as the laser beam 1, but is not particularly limited thereto.

[0062] The first optical functional part 10 further includes an optional optical shaping system 12, which is irradiated with the laser beam 1 from the light source 11. The optical shaping system 12 is designed to provide an irradiation shape of the laser beam 1, for example as shown in Fig. 1(a) into a rectangular radiation shape, for example as shown in Fig. 1(b). The laser beam 2, which has a rectangular irradiation shape, can provide a uniform irradiation energy density and has a beam profile of, for example, a cylindrical shape.

[0063] The optional second optical functional part 20 includes a mask 21. The mask 21 includes an effective area 22 with a pattern corresponding to the recess to be formed in the substrate 80. The size of the mask 21 is not particularly limited. For example, a mask 21 with an outer dimension of 700 mm × 800 mm and an effective area 22 of 600 mm × 600 mm can be used.

[0064] The mask 21 encloses an irradiated mask area that is to be irradiated with the laser beam 2 that has passed through the first optical functional part 10. This irradiated mask area is part of the effective area 22 of the mask 21.

[0065] The laser beam 3, which has passed through the second optical functional part 20 and has an irradiation form, for example as in Fig. 1(c), is reflected in its propagation direction by an optional reflecting mirror 50, as shown in Fig. 1(d), and enters an optional third optical functional part 30 (which will be described later). The ablation processing device 100 in the example of Fig. 1 is designed such that the laser beam 4 emitted from the third optical functional part 30 is directed onto a part of the substrate 80 held on the substrate positioning table 40.

[0066] The substrate 80 includes an irradiated substrate area onto which the pattern is projected by the laser beam that has passed through the mask 21 (and the optional third optical functional part 30).

[0067] In the example in Fig. 1, the mask 21 is designed to move along the travel axes 21X and 21Y in Fig. 1. The substrate positioning table 40 is also configured to be scanned (moved) along the scanning axes 80X and 80Y in Fig. 1 to be scanned.

[0068] The control unit 90 is designed to perform control such that an irradiation area in one shot of the laser beam 4 on the substrate 80 is set to be smaller than a region of the substrate 80 to be processed, and the substrate 80 is subjected to a plurality of shots of irradiation by the laser beam 4 to perform irradiation with the laser beam over an entire surface of the region of the substrate 80 to be processed, and in the plurality of irradiation shots, while the irradiation area of ​​the laser beam 4 is moved relative to the substrate 80 in each of a first direction of the substrate 80 (for example, a direction of the traversing axis 80X) and a second direction orthogonal to the first direction (for example, a direction of the traversing axis 80Y),a portion of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first and second directions to form a recess with a depth within a defined range in the area of ​​the substrate 80 to be processed. Such control is described in detail below. [Ablation processing method]

[0069] For example, the ablation processing method of the present invention can be performed using the ablation processing device of the present invention, but can also be performed using a device other than the ablation processing device of the present invention.

[0070] The following is an example of the method for ablation processing of the present invention, which is carried out using the method described in Fig. 1 shown device for ablation processing 100 is specifically described.

[0071] The ablation processing method of the present invention is an ablation processing method for forming a recess in the surface of the substrate 80 by ablation processing with irradiation energy of a laser beam 4.

[0072] In the method for ablation processing of the present invention, as shown schematically in Fig. 2, an irradiation area 41 in one shot of the laser beam 4 onto the substrate 80 is adjusted so that it is smaller than an area 8 of the substrate 80 to be processed.

[0073] Then, the substrate 80 is subjected to a plurality of irradiation shots with the laser beam 4 to perform the irradiation with the laser beam over the entire surface of the region 8 to be processed of the substrate 80.

[0074] In this case, in the method for ablation processing of the present invention, in the plurality of irradiation shots, while the irradiation area 41 of the laser beam 4 with respect to the substrate 80 overlaps in each of a first direction of the substrate 80 (for example, a direction of the scanning axis 80X in Fig. 1) and a second direction orthogonal to the first direction 80X (for example, a direction of the departure axis 80Y in Fig. 1), a part of the irradiation area 41 in each shot is moved with the irradiation area 41 in another shot in each of the first direction 80X and the second direction 80Y, so as to form a recess having a depth within a defined range in the area 8 to be processed of the substrate 80.

[0075] A specific example of the overlapping irradiation (hereinafter referred to as stitching) in the present invention will be described below. The depth within the defined range will be described below with reference to Fig. 7 and Fig. 8 described.

[0076] In the example of overlapping irradiation of Fig. 3 overlaps, while the irradiation areas 41A-1, 41B-1, 41C-1 and 41D-1 are moved in the first direction 80X with respect to the substrate 80, a part of the irradiation area 41A-1 overlaps with the irradiation areas 41B-1 and 41C-1 in the first direction 80X, a part of the irradiation area 41B-1 overlaps with the irradiation areas 41A-1, 41C-1 and 41D-1 in the first direction 80X, a part of the irradiation area 41C-1 overlaps with the irradiation areas 41A-1, 41B-1 and 41D-1 in the first direction 80X, and a part of the irradiation area 41D-1 overlaps with the irradiation areas 41B-1 and 41C-1 in the first direction 80X.

[0077] Such overlapping irradiation is carried out up to one shot of irradiation with a laser beam for an irradiation area 41Z-1 in Fig. 4 is repeated. Then, the irradiation area 41 of the laser beam 4 is moved relative to the substrate 80 in the first direction 80X and in the second direction 80Y orthogonal to the first direction 80X. More specifically, the irradiation area 41 is moved so that an irradiation area 41A-2 overlaps the previous irradiation areas 41A-1, 41B-1, and 41C-1 in the second direction 80Y. Then, the same overlapping irradiation as above is performed while moving the irradiation area 41 relative to the substrate 80 in the first direction 80X.

[0078] Fig. Fig. 5 shows an image of the overlapping irradiation performed while the irradiation area 41 is moved in each of the first direction 80X and the second direction 80Y in this way. Fig. 5(a), the overlapping irradiation is performed while the irradiation area 41 is moved relatively in the first direction 80X from the irradiation areas 41A-1 and 41B-1 to the irradiation areas 41Y-1 and 41Z-1. Next, in Fig. 5(b), the irradiation area 41 of the laser beam 4 is moved relative to the substrate 80 in the first direction 80X and the second direction 80Y orthogonal to the first direction 80X, and then, while the irradiation area 41 is moved relative to the substrate 80 in the first direction 80X, the irradiation with the laser beam is performed from the irradiation area 41A-2 to an irradiation area 41Z-2 in order to achieve the overlap on the irradiation areas 41A-1 to 41Z-1 in the second direction 80Y and also to achieve the same overlap in the first direction 80X as before. Next, in Fig. 5(c) the irradiation area 41 of the laser beam 4 is moved relative to the substrate 80 in the first direction 80X and the second direction 80Y orthogonal to the first direction 80X, and then, while the irradiation area 41 is moved relative to the substrate 80 in the first direction 80X, the irradiation with the laser beam is carried out from an irradiation area 41A-3 to an irradiation area 41Z-3 to overlap on the irradiation areas 41A-1 to 41Z-1 formed in the first step of Fig. 5(a), and on the irradiation areas 41A-2 to 41Z-2 formed in the step of Fig. 5(b) were irradiated in the second direction 80Y and also to achieve the same overlap in the first direction 80X as before. Then, the steps described above are repeated until the entire surface of the area of ​​the substrate to be processed has been irradiated with the laser beam.

[0079] Fig. Figure 6 is a schematic plan view of a part of the substrate after the overlapping irradiation of Fig. 5. Fig. 6 illustrates a result of the fact that, while the irradiation region 41 is moved in one shot relative to the substrate 80 in each of the first direction 80X and the second direction 80Y, a part of the irradiation region 41 in each shot overlaps with the irradiation region 41 in another shot in each of the first direction 80X and the second direction 80Y, as shown in Fig. 5. More specifically, in the first direction overlap 80X, one-fourth of a width of the irradiation area 41 in one shot in the first direction 80X overlaps with the irradiation area 41 in a previous shot. In the second direction overlap 80Y, one-third of the width of the irradiation area 41 in one shot in the second direction 80Y overlaps each of the other irradiation areas 41 located above and below in the second direction 80Y. Note that this example of overlap is merely an example, and the degree of overlap is not particularly limited in the present invention. The degree of overlap may be changed depending on the location.

[0080] In the examples in Fig. 5 and Fig. 6, the departure direction in the first direction 80X is the same in the first, second and third rows (from left to right on the page), but the departure direction can be changed, for example, between even and odd rows, or the departure direction can be vertical (the second direction 80Y in Fig. 6).

[0081] Fig. 6 illustrates an irradiation area 41I in a first shot, an irradiation area 41X in a tenth shot, an irradiation area 41XX in a twentieth shot, and an irradiation area 41XXX in a thirtieth shot in succession along the first direction 80X. Fig. 6 also represents, along the second direction 80Y, a series of a first row 41-1 to an eighth row 41-8 of overlapping irradiation in the first direction in sequence.

[0082] In Fig. 6, a collection of regions with four or more overlaps in the first direction 80X and three or more overlaps in the second direction forms an effectively machined region 82, which is a uniformly irradiated section. This effectively machined region 82 corresponds to the recess to be machined.

[0083] In the ablation processing method of the present invention, the overlapping irradiation described in detail above is performed to form the recess having a depth within a defined range in the region 8 to be processed of the substrate 80.

[0084] Fig. Figure 7 represents a specific example. In the flow of Fig. 7, the upper part is a plan view of an irradiation mold 41 in each shot, and a lower part is a cross-sectional view of the substrate 80 after each shot. In the upper part of Fig. 7, the area of ​​laser irradiation in this shot is enclosed by a dashed frame, and traces of the previous laser irradiation are shown without a frame.

[0085] In a first shot, as in Fig. As shown in Fig. 7(a), the laser beam 4 is applied to the substrate 80 with an irradiation pattern 41A to form a recess 83a.

[0086] In a second shot, as in Fig. As shown in Figure 7(b), the laser beam 4 is applied to the substrate 80 with an irradiation pattern 41B to form a recess 83b. The recess 83b has a portion 84b formed by overlapping irradiation in the first and second shots and has a greater depth than the recess 83a.

[0087] In a third shot, as in Fig. As shown in Figure 7(c), the laser beam 4 is applied to the substrate 80 with an irradiation pattern 41C to form a recess 83c. The recess 83c has a portion 84c formed by overlapping irradiation in the first, second, and third shots and has a depth greater than the maximum depth of the recess 83c.

[0088] In a fourth shot, as in Fig. As shown in Figure 7(d), the laser beam 4 is applied to the substrate 80 with an irradiation pattern 41D to form a recess 83d. The recess 83d has a portion 84d formed by overlapping irradiation in the first, second, third, and fourth shots and has a maximum depth 85 that is greater than a maximum depth of the recess 83c.

[0089] In a fifth shot, as in Fig. As shown in Figure 7(e), the laser beam 4 is applied to the substrate 80 with an irradiation pattern 41E to form a recess 83e. The recess 83e includes a portion 84e formed by overlapping irradiation in the second, third, fourth, and fifth shots, adjacent to the portion 84d formed in the fourth shot, and having the maximum depth. This portion 84e is formed by the energy of four shots of the laser beam 4, and thus, a maximum depth of the portion 84e is the same as the maximum depth 85 of the portion 84d, which is also formed by the energy of four shots of the laser beam 4.

[0090] In a sixth shot, as in Fig. As shown in Figure 7(f), the laser beam 4 is applied to the substrate 80 with an irradiation pattern 41F to form a recess 83f. The recess 83f includes a portion 84f formed by overlapping irradiation in the third, fourth, fifth, and sixth shots, adjacent to the portion 84e formed in the fifth shot, and having the maximum depth. This portion 84f is formed by the energy of four shots of the laser beam 4, and thus, a maximum depth of the portion 84f is the same as the maximum depth 85 of the portion 84e, which is also formed by the energy of four shots of the laser beam 4.

[0091] By performing the overlapping irradiation in a seventh shot in the same way and so on, a depression 83z is finally formed, as in Fig. 7(g). A portion 84z having a maximum depth of the recess 83z is formed by the energy of four shots of the laser beam 4 similar to the portion 84d having the maximum depth 85 of the recess 83d, and thus the maximum depth of the portion 84z is the maximum depth 85.

[0092] Fig. Fig. 7 illustrates the depth of the recess formed by the overlapping irradiation performed while the irradiation area 41 is moved relative to the substrate 80 in the first direction (for example, in the direction of the scanning axis 80X in Fig. 1). In the method for ablation processing of the present invention as described with reference to Fig. 5 and Fig. 6, the overlapping irradiation is carried out while the irradiation area 41 is also irradiated in the second direction orthogonal to the first direction (for example, the direction of the scanning axis 80Y in Fig. 1) so that the resulting depression has the maximum depth within a defined area.

[0093] The depth within the defined range in the present invention is within a range of the depth of the recess that can be formed in the substrate 80. For example, if a recess with a depth of 15 µm is to be formed, the depth within the specified range may be 15 µm ± 3 µm.

[0094] In this way, with the ablation processing method of the present invention, a recess having a desired depth can be obtained on the substrate 80 with a simple operation while preventing penetration of the layer caused by excessive processing.

[0095] As a variant, as in Fig. 8, for example, sections with different maximum depths can be periodically formed by changing the degree of overlap between the shots. In particular, Fig. 7(e) the irradiation area 41E in the fifth shot does not coincide with the irradiation area 41A in the first shot, while a part of the irradiation area 41E in the fifth shot, as in Fig. 8(e), can overlap with the irradiation area 41A in the first shot to form a section 86 with a maximum depth 87. Then, as shown in Fig. 8(f), a part of the irradiation area 41F in the sixth shot may be overlapped with the irradiation area 41B in the second shot to the same extent as the overlap of the irradiation area 41E in the fifth shot and the irradiation area 41A in the first shot, as shown in Fig. 8(e) to form another section 86 having the maximum depth 87, which is the same as that formed by irradiation in the fifth shot. Subsequently, the same overlap can be repeated periodically to form a plurality of recesses 86 periodically arranged in a direction 86A in a bottom of the recess 83z, as shown in Fig. 8(g). It is important to perform the overlapping irradiation such that the maximum depth 87 of each of the plurality of sections 86 lies within the range described above.

[0096] The overlapping irradiation described above can also be carried out, for example, without using the mask 21 in Fig. 1. On the other hand, by using the mask 21 in Fig. 1 Ablation processing of various fine patterns can be performed.

[0097] When using the mask 21, it is preferable that an irradiated mask region, which is a part of the effective area 22 of the mask 21, is irradiated with the laser beam 2 from the light source 11, an irradiated substrate region, which is at least a part of the region 8 to be processed of the substrate 80, is irradiated with the laser beam 4 passed through the mask 21 to project a pattern onto the irradiated substrate region to thereby perform the ablation processing, and when moving the irradiation region 41 of the laser beam 4 with respect to the substrate 80, the mask 21 and the substrate 80 are synchronously moved in a planar direction substantially perpendicular to an irradiation direction of the laser beam 4.

[0098] In this preferred aspect, the area to be machined is not limited to an area of ​​a lens (for example, the third optical functional part 3), and thus an area (angle of view) larger than the area of ​​the lens can be machined.

[0099] Furthermore, according to this aspect, a reduction-in-size projection optical system 31 (described later) required for irradiation can be downsized, and the positional accuracy of laser irradiation and temperature control can be improved. Furthermore, the size of the reduction-in-size projection optical system 31 can be reduced, thereby reducing image distortion caused by irradiation.

[0100] Furthermore, the irradiated mask area of ​​the mask 21 is preferably irradiated with the laser beam 2 having a rectangular irradiation shape, for example, by using the ablation processing device 100 as shown in Fig. 1 is used.

[0101] In this way, the substrate 80 can be irradiated with the laser beam 4 having the rectangular irradiation shape 41. Irradiation with the laser beam 4 having such a rectangular irradiation shape can more reliably prevent penetration of the layer caused by excessive processing.

[0102] In particular, rectangular irradiation allows more efficient and precise control of the position and number of irradiations with microscopic overlap than, for example, irradiation with circular overlap.

[0103] The irradiation with the laser beam 4 is preferably carried out without stopping the mask 21 and the substrate 80 during the plurality of irradiation shots in the first direction 80X and / or the second direction 80Y.

[0104] This enables more efficient ablation processing.

[0105] Further, when the mask 21 is used, a first mask and a second mask may be used as the mask 21, the plurality of irradiation shots may be performed using the first mask, the first mask may then be replaced with the second mask, and the plurality of irradiation shots may be performed using the second mask, so that a part of the irradiated substrate area of ​​the substrate 80 in the first direction overlaps with a part of the irradiated substrate area in the plurality of irradiation shots using the first mask.

[0106] For example, the first row 41-1 to the fourth row 41-4 of the overlapping irradiation in Fig. 6 using the first mask, and the fifth row 41-5 to the eighth row 41-8 of the overlapping irradiation in Fig. 6 may be performed using the second mask that has replaced the first mask. In this case, the first mask and the second mask may be arranged in a second direction 80Y relative to the substrate 80.

[0107] In this case, the irradiation with the laser beam can be performed without stopping the first mask and the substrate 80 during the multiple irradiation shots using the first mask, and the irradiation with the laser beam can be performed without stopping the second mask and the substrate 80 during the multiple irradiation shots using the second mask.

[0108] In this way, in the ablation processing method of the present invention, laser beam irradiation can be performed without stopping the first mask and the substrate 80 while using the first mask, and laser beam irradiation can be performed without stopping the second mask and the substrate 80 while using the second mask. This enables more efficient and reliable ablation processing.

[0109] Alternatively, when using two or more masks, the ablation processing can be performed as described in Fig. 10, according to the flow chart in Fig. 9 be carried out.

[0110] In the ablation processing procedure of the example in Fig. 9 and Fig. 10, the first mask is first positioned relative to the substrate 80.

[0111] As in Fig. As shown in Figure 10(a), the scanning processing with the first mask is performed using the positioned first mask. The scanning processing here is, for example, the overlapping irradiation in the process as shown in Fig. 8(a) to 8(g), but is not limited thereto. Through this scanning processing, a recess 83A corresponding to the irradiated mask area of ​​the first mask can be formed.

[0112] Then, the first mask is replaced by the second mask, and the starting position for processing the substrate is changed so that a recess 83B to be processed next is located next to the already processed recess 83A. In this example, the substrate processing position is typically moved in the first direction 80X.

[0113] Then the second mask is positioned relative to the substrate 80.

[0114] As in Fig. As shown in Figure 10(b), the scanning processing with the second mask is performed using the positioned second mask. The scanning processing here is, for example, the overlapping irradiation in the process as shown in Fig. 8(a) to 8(g), but is not limited thereto. Through this scanning processing, the recess 83B corresponding to the irradiated mask area of ​​the second mask can be formed.

[0115] Subsequently, the ablation processing is carried out by overlapping irradiation, if necessary repeatedly in the first direction 80X and the second direction 80Y, as for example in Fig. 5 and Fig. 6 shown.

[0116] Then, the stitching is finally completed and the desired recess 83c can be formed in the surface of the substrate 80, as shown in Fig. 10(c).

[0117] By using two or more masks while changing the substrate processing position, the area of ​​the substrate to be processed, which has a larger area than the substrate processing area corresponding to the effective area of ​​the mask, can be processed by patchwork processing.

[0118] The control unit 90 in Fig. 1 is designed, for example, to control the overlapping irradiation described above. For example, the control unit 90 in the ablation processing device 100 is Fig. 1 is electrically connected to the mask 21 and the substrate positioning table 40. The control unit is further preferably configured to synchronously move a mask positioning table (not shown) supporting the mask 21 and the substrate positioning table 40 in a planar direction substantially orthogonal to an irradiation direction of the laser beam 4 (for example, to synchronize a movement along the scanning axis 21X with a movement along the scanning axis 80X and to synchronize a movement along the scanning axis 21Y with the movement along the scanning axis 80Y).

[0119] The facility for ablation processing 100 in Fig. 1 also includes a mask alignment camera 23 as an imaging device for reading characteristic portions of the mask 21 and a substrate alignment camera 60 as an imaging device for reading characteristic portions of the substrate 80. The mask alignment camera 23 is configured to send position information about the characteristic portions of the mask 21 to the control unit 90. The substrate alignment camera 60 is configured to send position information about the characteristic portions of the substrate 80 to the control unit 90. The control unit 90 is configured to adjust the relative positions of the substrate 80 and the mask 21 based on the position information.

[0120] The facility for ablation processing 100 in Fig. 1 further includes the third optical functional part 30 with the optional reduction optical projection system 31 between the second optical functional part 20 and the substrate positioning table 40.

[0121] In recent years, substrate processing has become increasingly fine, with a desired minimum processing width of several micrometers. This can also be affected by fine dust, and in particular, fine dust adhering to a mask part can cause a large number of processing defects. Thus, the mask 21 is formed larger than an actual processing pattern, and the laser beam 3 passing through the mask 21 is subjected to a reduction projection exposure by the downstream reduction optical projection system 31, thereby minimizing the influence of fine dust.

[0122] Furthermore, the mask 21 is formed larger than the actual machining pattern, thereby allowing the energy of the laser beam 2 incident on the mask 21 to be lower than the machining energy. When a reduction amount of the projection optical system with reduction 31 is N, the energy of the laser beam incident on the mask surface is 1 / (N 2 ) compared to the processing energy on the surface of the substrate 80. This can suppress the thermal drift caused by the energy of the laser beam 2, thereby suppressing thermal expansion of the mask 21 and enabling processing to be performed with high accuracy even after a long processing operation.

[0123] Furthermore, damage to the optical components (e.g., the optical forming system 12 and the mask 21) caused by the heat emitted from the laser beam can be suppressed, thereby increasing the lifetime of the optical components.

[0124] The reduction projection optical system 31 may include a pair of reduction projection lenses. If the reduction projection optical system 31 is an infinity optical system, the reduction of the reduction projection optical system 31 may be adjusted, for example, by a ratio between the focal lengths of the reduction projection lenses and the distance between the reduction projection lenses.

[0125] The NA of the reduction projection lens is preferably selected according to the energy density required for processing the substrate 80. The NA of the reduction projection lens is preferably 0.12 or more.

[0126] The third optical functional part 30 preferably includes a temperature adjusting means for adjusting a temperature of the reduction projection optical system 31.

[0127] By providing the temperature adjustment means, the influence of heat of the laser beam energy in the reduction-projection optical system 30 can be further reduced. Through the reduction-projection optical system 30, the laser beam 3 passing through the mask 21 undergoes a reduction projection of 1 / N. Thus, the energy of the laser beam passing through a lens part at the tip of an objective lens is N 2-times the energy of the laser beam incident on the mask 21, and this part is susceptible to thermal effects. Therefore, by providing the reduction-type projection optical system 30 with the temperature adjustment function for reducing thermal energy, the thermal drift caused by the laser beam energy can be suppressed, and machining can be performed with high precision even after a long machining process.

[0128] In the ablation processing method and ablation processing apparatus of the present invention, a reduction projection lens with a very small aperture can be used. The temperature adjusting means for the reduction projection lens cannot be provided directly on the lens itself, but cools a jacket holding the lens. Thus, when the lens has a larger aperture, temperature control can be achieved for a peripheral part of the lens, but for a substantial central part, a temperature adjusting effect is insufficient, and temperature control is difficult. Therefore, even a small amount of energy absorption in the lens caused by prolonged laser irradiation can easily lead to heat-induced distortion. With the third optical functional part 30 having a temperature adjusting function, the lens aperture can be small, thereby avoiding such defects.

[0129] Furthermore, the defects caused by the irradiation of a laser beam on the reduction projection optical system 31 can be avoided to extend the service life of the reduction projection optical system 31.

[0130] The facility for ablation processing 100 in Fig. 1 further includes an optional beam image capture camera 70 in addition to the optional mask alignment camera 23 and the optional substrate alignment camera 60.

[0131] The shape of the projection image of the pattern of the mask 21 does not always exactly correspond to the processing shape of the substrate 80, and the magnification is also not always the same due to the influence of thermal expansion or the like. Furthermore, due to a slight distortion or deformation of the substrate 80, it may be necessary to deform the processing shape of the substrate 80 with respect to the projection image of the mask 21.

[0132] Thus, the positions of the mask 21 and the substrate 80 are obtained by the mask alignment camera 23 and the substrate alignment camera 60, and based on the information, the projection image of the mask 21 is adapted to the shape of the substrate to be processed, thereby enabling precise formation of unevenness in the substrate.

[0133] Specifically, for example, the projection position of the projection image of the mask 21 is obtained by the beam image acquisition camera 70 and corrected based on the information about the projection position to optimize the projection reduction of the third optical functional part 30 and optimize the retraction speed during ablation processing based on the information. This allows the vertical and horizontal magnifications and reductions of the substrate 80 with respect to the image of the mask 21 to be arbitrarily changed to a certain extent, thus enabling the application of an optimal substrate processing form.

[0134] The substrate to be processed by the ablation processing method and the ablation processing apparatus of the present invention is not particularly limited, but may be, for example, a semiconductor package substrate.

[0135] In particular, the processing of the semiconductor package substrate may include a processing pattern combining VIA processing and groove processing, or the like. In this case, the method of the present invention allows the VIA processing and groove processing to be performed in the same step without separating them from each other.

[0136] Furthermore, semiconductor package substrates are increasingly exhibiting denser configurations. A conventional laser drilling method for VIA processing increases processing time due to the increased number of holes to be drilled, which is associated with higher density. In comparison, the method of the present invention does not result in an increase in processing time due to a larger number of holes to be drilled or a finer pattern.

[0137] Components of the substrate area to be processed are not particularly limited, but may include, for example, epoxy resin, polyimide resin, and ABS resin (acrylonitrile butadiene styrene copolymer resin).

[0138] In the present invention, for example, an excimer laser can be used as the laser beam.

[0139] Irradiation with a single shot of a pulsed excimer laser beam can form a recess with a depth of approximately 0.5 µm in a region to be processed on a surface of the substrate containing these materials. In the present invention, a desired depth is divided by the number of shots of the laser beam, and overlapped irradiation is performed so that a processing depth does not exceed a certain depth. Thus, the present invention can obtain a recess with a desired depth with a simple process while preventing penetration of the layer caused by excessive processing.

[0140] Furthermore, using an excimer laser allows for efficient ablation of the surface to be processed on an organic material substrate, such as an ABF substrate, and allows for high productivity. Furthermore, the excimer laser has low coherence, allowing for more precise control of the position and number of microscopically overlapping irradiations. [Substrate]

[0141] The substrate of the present invention is, for example, the substrate 80 having the cross section as shown in Fig. 8(g). More specifically, the substrate 80 has the recess 83z as a groove (trench), and the bottom of the groove 83z has a plurality of recesses 86 periodically arranged in a longitudinal direction 86A of the groove 83z.

[0142] In such a substrate 80, the plurality of recesses 86 periodically arranged in the longitudinal direction 86A of the groove 83z can provide an anchoring effect for fixing a layer or the like formed on the substrate 80, thereby achieving high reliability. With such a substrate, an embedded conductive layer is less likely to peel off, which may occur during a coating step or CMP performed after the ablation processing step in the present invention, and a high-quality final product having high resistance to stress caused by thermal cycling or the like can be provided after completion of the processing.

[0143] Furthermore, the presence of a plurality of depressions 86 can provide a desired change in electrical conductivity.

[0144] The substrate 80 of the present invention is, for example, a semiconductor package substrate, but is not limited thereto. [Method for producing the substrate]

[0145] An example of a method for manufacturing a substrate of the present invention is a processing method including a series of steps as schematically shown in Fig. 8. The method of manufacturing a substrate according to the present invention may be an aspect of the method of ablation processing of the present invention.

[0146] Generally, with reference to Fig. 1, Fig. 2 and Fig. 8, the method for manufacturing a substrate of the present invention is a method for manufacturing a substrate 80 having a groove 83z in a surface of the substrate 80 by ablation processing with irradiation energy of a laser beam, wherein an irradiation area 41 in one shot of the laser beam 4 on the substrate 80 is set to be smaller than a region 8 of the substrate 80 to be processed, and the substrate 80 is subjected to a plurality of irradiation shots with the laser beam 4 to perform irradiation with the laser beam over an entire surface of the region 8 of the substrate 80 to be processed, and wherein, in the plurality of irradiation shots, while the irradiation area 41 of the laser beam 4 is moved with respect to the substrate 80 in each of a first direction 80X of the substrate 80 and a second direction 80Y orthogonal to the first direction 80X,a part of the irradiation region 41 in each shot overlaps with the irradiation region 41 in another shot in each of the first direction 80X and the second direction 80Y, so as to form the groove 83z with a depth within a defined range in the region 8 to be processed of the substrate 80, wherein the plurality of irradiation shots are performed such that irradiation regions with different numbers of overlaps are provided in each of the first direction 80X and the second direction 80Y, and thereby the substrate in which a bottom of the groove 80z has a plurality of recesses 86 periodically arranged in the longitudinal direction 86A of the groove 83z is produced.

[0147] By this method of manufacturing a substrate, the substrate of the present invention can be manufactured.

[0148] It should be noted that the ablation method of the present invention can produce the substrate in which the bottom of the groove 83z has the plurality of recesses 86 periodically arranged in the longitudinal direction 86A of the groove 83z, as shown in Fig. 8(g), and can also produce a substrate in which no plurality of recesses are formed in the bottom of the groove 83z as shown in Fig. 7(g).

[0149] The control of the formation of depressions in the groove is described below.

[0150] Fig. 11 illustrates an example of overlapping irradiation according to the present invention for forming a recess 86 in a groove 8a formed in the region 8 to be processed. On the left is a schematic plan view of the irradiation region 41, on the right is a schematic plan view of the first row 41-1 and the second row 41-2 of overlapping irradiation on the region 8 to be processed, and in the middle is a schematic cross-sectional view of the region 8 to be processed after the first row 41-1 and the second row 41-2 of overlapping irradiation.

[0151] The overlapping irradiation in Fig. 11 is an example of a regular scanning and the overlapping irradiation of the rectangular irradiation area 41. More specifically, in the overlapping irradiation in Fig. 11, a long side of the rectangular irradiation area 41 is set to be parallel to the second direction 80Y, and a short side is set to be parallel to the first direction 80X, and the second row 41-2 of overlapping irradiation along the first direction 80X is performed so as to partially overlap, in the direction parallel to the second direction 80Y, the second row 41-2 on the first row 41-1 of overlapping irradiation along the first direction 80X. The recess 86 is formed in an overlap region 41a of the first row 41-1 and the second row 41-2 within a defined depth range.

[0152] On the other hand, as in Fig. 12, the long side of the rectangular irradiation area 41 is tilted with respect to the second direction 80Y and the second row 41-2 of the overlapping irradiation along the first direction 80X is performed such that, in the direction parallel to the second direction 80Y, the second row 41-2 partially overlaps with the first row 41-1 of the overlapping irradiation along the first direction 80X, the number of overlaps of the first row of the first row 41-1 and the second row 41-2 in an overlapping section 41b is smaller than the number of overlaps in the overlapping section 41a in the example in Fig. 11. As in Fig. 12, this can be the formation of the recess 86 in the groove 8a as in the example of Fig. 11 suppress.

[0153] The irradiation area 41 may be tilted, for example, by tilting the laser beam with respect to the moving directions of a photomask and the substrate (for example, 21X, 21Y, 80X and 80Y in Fig. 1). If the photomask and positioning stage are actually tilted, the laser beam itself does not necessarily need to be moved.

[0154] The means to suppress the formation of the depression are not limited to the example in Fig. 12, but can be a procedure, as in the example of Fig. 13. In the example of Fig. 13, the laser beam is cut at an angle before and after the photomask to deform the irradiation area 41. For example, a metal plate 24 is attached to one side or both sides of the photomask. If the irradiation area 41 is formed as shown in Fig. 13 and the second row 41-2 of the overlapping irradiation along the first direction 80X is carried out such that the second row 41-2 partially overlaps in the direction parallel to the second direction 80Y with the first row 41-1 of the overlapping irradiation along the first direction 80X, the number of overlaps of the first row 41-1 and the second row 41-2 in an overlapping section 41c is smaller than the number of overlaps in the overlapping section 41a in the example of Fig. 11.

[0155] It should be noted that, as in Fig. 14, if the second row 41-2 of overlapping irradiation could be performed such that the second row 41-2 in the second direction 80Y does not overlap with the first row 41-1 of overlapping irradiation along the first direction 80X, that is, if the overlap is not performed in a region 41d, the formation of the recess in the groove could be completely prevented. However, overlapping irradiation under such control is actually difficult. For example, as shown in Fig. 15(a), there may be a misalignment portion 41e between the first row 41-1 and the second row 41-2 without overlap, or as shown in Fig. 15(b), the first row 41-1 and the second row 41-2 may overlap each other in an overlap portion 41f.

[0156] On the other hand, for example, if at most four overlaps of the irradiation can form a groove, while the formation of the depression in the ground is reduced to a desired level by tilting the irradiation area and performing the first row 41-1 and the second row 41-2 of the overlapping irradiation as in the example in Fig. 16, the number of overlaps in an overlap section 41e becomes four, and the formation of the recess 86 can be reduced to a desired level, although the depth of the bottom of the groove is not completely uniform. Thus, by the method of deforming the irradiation area 41 as shown in Fig. 13, the formation of the depression can be suppressed in a similar way.

[0157] If the bottom of the groove 83z has a plurality of recesses 86, as in the case described with reference to Fig. With the substrate 80 described in Figure 8(g), an anchoring effect can be achieved for a metal electrode or the like embedded in a stopper-machined (trench-machined) portion. In the ablation machining method of the present invention, the recess having a depth within a defined range is formed in the region of the substrate to be machined, thereby preventing excessive machining of the substrate and insufficient machining depth.

[0158] As in Fig. As shown in Fig. 7(g), by forming the groove 83z while suppressing the formation of the recess in the bottom, penetration of the substrate 80 to be machined or defects (increased electrode resistance) due to insufficient machining depth or the like can be more reliably prevented.

[0159] Furthermore, according to the method described with reference to, for example, Fig. 12, Fig. 13 and Fig. 16, the unevenness in the ground at the seams of the ablation processing is controlled and the unevenness is reduced, thus enabling high-quality trenching.

[0160] The present description includes the following embodiments: [1] An ablation machining method for forming a recess in a surface of a substrate by ablation machining with irradiation energy of a laser beam, wherein an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be machined, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be machined, and wherein, in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved with respect to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction,in order to form the recess with a depth within a defined range in the area of ​​the substrate to be processed. [2] The method for ablation processing according to [1], wherein in the plurality of irradiation shots, a light source that generates the laser beam by oscillation and a mask including an effective area with a pattern corresponding to the recess to be formed are used, an irradiated mask region, which is a part of the effective area of ​​the mask, is irradiated with the laser beam from the light source, an irradiated substrate region, which is at least a part of the region of the substrate to be processed, is irradiated with the laser beam passed through the mask to project a pattern onto the irradiated substrate region to thereby perform the ablation processing, and when the irradiation region of the laser beam is moved with respect to the substrate, the mask and the substrate are synchronously moved in a planar direction substantially perpendicular to an irradiation direction of the laser beam. [3] The method for ablation processing according to [2], wherein the irradiated mask area of ​​the mask is irradiated with the laser beam having a rectangular irradiation shape. [4] The method for ablation processing according to [2] or [3], wherein the irradiation with the laser beam is performed without stopping the mask and the substrate during the plurality of irradiation shots in the first direction and / or the second direction. [5] The method for ablation processing according to one of [2] to [4], wherein a first mask and a second mask are used as a mask, the plurality of irradiation shots are carried out using the first mask, the first mask is then replaced by the second mask, and the plurality of irradiation shots are performed using the second mask such that a part of the irradiated substrate area of ​​the substrate in the first direction overlaps with a part of the irradiated substrate area in the plurality of irradiation shots using the first mask. [6] The method for ablation processing according to any one of [1] to [5], wherein an excimer laser is used as the laser beam. [7] A method for ablation processing according to any one of [1] to [6], wherein a semiconductor package substrate is subjected to the ablation processing as the substrate. [8] An ablation machining apparatus for forming a recess in a surface of a substrate by ablation machining with irradiation energy of a laser beam, comprising a light source that generates the laser beam by oscillation; a substrate positioning table that supports the substrate; and a control unit configured to perform control such that an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be machined, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be machined, and wherein in the plurality of irradiation shots, while the irradiation area of ​​the laser beam with respect to the substrate in each of a first direction of the substrate and a second,is moved in a direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the recess with a depth within a defined range in the area of ​​the substrate to be processed. [9] The ablation processing apparatus according to [8], further comprising: a mask enclosing an effective area having a pattern corresponding to the area of ​​the substrate to be processed; and a mask positioning table supporting the mask, wherein the control unit is further configured to synchronously move the mask positioning table and the substrate positioning table in a planar direction substantially perpendicular to an irradiation direction of the laser beam.

[10] The ablation processing apparatus according to [9], further comprising: between the light source and the mask, an optical shaping system that shapes an irradiation shape of the laser beam into a rectangular irradiation shape.

[11] The ablation processing device according to any one of [8] to

[10] , wherein the light source is an excimer laser light source.

[12] A substrate having a groove in a surface of the substrate, wherein a bottom of the groove has a plurality of recesses periodically arranged in the longitudinal direction of the groove.

[13] Substrate according to

[12] , wherein the substrate is a semiconductor package substrate.

[14] A method for manufacturing a substrate having a groove in a surface of the substrate by ablation processing with irradiation energy of a laser beam, wherein an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, wherein in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved with respect to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction,so as to form the groove with a depth within a defined range in the region of the substrate to be processed, wherein the plurality of irradiation shots are carried out such that irradiation regions with different numbers of overlaps are provided in each of the first direction and the second direction, and thereby the substrate in which a bottom of the groove has a plurality of recesses periodically arranged in the longitudinal direction of the groove is produced.

[0161] It should be noted that the present invention is not limited to the embodiments described above. This embodiment is merely an example, and any examples having substantially the same features and exhibiting the same functions and effects as those in the technical concept disclosed in the claims of the present invention are included within the technical scope of the present invention. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] WO 2013 / 094025 A1

[0005]

Claims

[1] A method for ablation processing for forming a recess in a surface of a substrate by ablation processing with irradiation energy of a laser beam, wherein an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, and in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved with respect to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the recess having a depth within a defined range in the area of ​​the substrate to be processed. [2] The method of ablation processing according to claim 1, wherein in the plurality of irradiation shots a light source that generates the laser beam by oscillation and a mask that encloses an effective area with a pattern corresponding to the recess to be formed, an irradiated mask area, which is a part of the effective area of ​​the mask with which the laser beam from the light source is irradiated, an irradiated substrate area, which is at least a part of the area of ​​the substrate to be processed, is irradiated with the laser beam passed through the mask to project a pattern onto the irradiated substrate area to thereby perform the ablation processing, and when the irradiation area of ​​the laser beam is moved relative to the substrate, the mask and the substrate are moved synchronously in a planar direction substantially perpendicular to an irradiation direction of the laser beam. [3] The ablation processing method according to claim 2, wherein the irradiated mask portion of the mask is irradiated with the laser beam having a rectangular irradiation shape. [4] The ablation processing method according to claim 2, wherein the irradiation of the laser beam is performed without stopping the mask and the substrate during the plurality of irradiation shots in the first direction and / or the second direction. [5] A method for ablation processing according to any one of claims 2 to 4, wherein a first mask and a second mask are used as a mask, the plurality of irradiation shots are carried out using the first mask, the first mask is then replaced by the second mask, and the plurality of irradiation shots are performed using the second mask such that a part of the irradiated substrate area of ​​the substrate in the first direction overlaps with a part of the irradiated substrate area in the plurality of irradiation shots using the first mask. [6] The ablation processing method according to any one of claims 1 to 4, wherein an excimer laser is used as the laser beam. [7] A method for ablation processing according to any one of claims 1 to 4, wherein a semiconductor package substrate is subjected to the ablation processing as the substrate. [8] An ablation processing device for forming a recess in a surface of a substrate by ablation processing with irradiation energy of a laser beam, comprising: a light source that generates the laser beam by oscillation; a substrate positioning table supporting the substrate; and a control unit configured to perform a control such that an irradiation area in one shot of the laser beam on the substrate is set to be smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, and in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved with respect to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the recess having a depth within a defined range in the area of ​​the substrate to be processed. [9] The ablation processing device of claim 8, further comprising: a mask enclosing an effective area with a pattern corresponding to the area of ​​the substrate to be processed; and a mask positioning table which supports the mask, whereby the control unit is further configured to synchronously move the mask positioning table and the substrate positioning table in a planar direction substantially perpendicular to an irradiation direction of the laser beam. [10] The ablation processing apparatus according to claim 9, further comprising: between the light source and the mask, an optical shaping system that shapes an irradiation shape of the laser beam into a rectangular irradiation shape. [11] An ablation processing device according to any one of claims 8 to 10, wherein the light source is an excimer laser light source. [12] A substrate having a groove in a surface of the substrate, wherein a bottom of the groove has a plurality of recesses periodically arranged in the longitudinal direction of the groove. [13] The substrate of claim 12, wherein the substrate is a semiconductor package substrate. [14] A method for producing a substrate having a groove in a surface of the substrate by ablation processing with irradiation energy of a laser beam, wherein an irradiation area in one shot of the laser beam on the substrate is set so that it is smaller than a region of the substrate to be processed, and the substrate is subjected to a plurality of irradiation shots with the laser beam in order to perform irradiation with the laser beam over an entire surface of the region of the substrate to be processed, in the plurality of irradiation shots, while the irradiation area of ​​the laser beam is moved relative to the substrate in each of a first direction of the substrate and a second direction orthogonal to the first direction, a part of the irradiation area in each shot overlaps with the irradiation area in another shot in each of the first direction and the second direction, so as to form the groove with a depth within a defined range in the area of ​​the substrate to be processed, the plurality of irradiation shots are carried out such that irradiation areas with different numbers of overlaps are provided in each of the first direction and the second direction, and thereby producing the substrate in which a bottom of the groove has a plurality of recesses periodically arranged in the longitudinal direction of the groove.

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